DESCRIPTION: The Longitudinal Studies and Statistical Core seeks to provide innovative and coordinated services for MRRC projects using human subjects and/or engaged in sophisticated biomathematical modeling of biological and behavioral phenomena. The Core lists seven specific objectives consistent with this overall aim. (1) To strengthen the advanced level of statistical expertise among MRRC investigators engaged in longitudinal research and/or mathematical modeling. (2) To promote the conduct of promising cross-product analyses of meta-analyses and the application of innovative methodologies in developmental science, including fostering new multi-disciplinary inquiries. (3) To facilitate design of multi-disciplinary research studies by capitalizing on advances in quantitative methods. (4) To provide ongoing workshops and advanced training in statistical methods, database management, tracking and cohort maintenance, and data archiving to MRRC investigators, staff, and trainees. (5) To provide consultation in design and operation of data management systems relating to data entry, editing, file organization, data reduction, and data retrieval. (6) To consult with investigators on subject recruitment and cohort maintenance. (7) To acquire and build an institutional resource in the form of increased access to longitudinal studies through public use datasets that contain data on development in normal and mental retarded and developmentally disabled populations. The Core is administered by two Co-Directors and includes a User Advisory Committee consisting of the core faculty and three additional core users. The Co-Directors meet monthly with staff to review operations, plan, and prioritize activities. The Core not only provides access to personnel for consultation and services, but is also described as providing access to hardware and software. The hardware resources available to MRRC investigators and listed under this Core are substantial. These include multiple servers, some with dedicated functions, and mainframe computers, RAID based storage systems, a ubiquitous fast Ethernet network, access to high speed scanning and automated tape backup systems, a variety of network printers, access for remote users, public and private Web servers, and access to the Internet. Software resources are equally substantial, including a variety of general purpose and specialty statistical programs, programming languages, and modeling tools running on a variety of platforms.